Weighted residual variance in a mixed model

Hi,
I am analysing genetic data using the model specified below. It is the first time I use ASREML. I tried to read the user's guide to specify the variance structure for the model but failed. Any help from anyone is highly appreciated.

yi = mu + ai + ei

where yi is the mean of observations from ni daughters of sire i. ai is the additive genetic effect of sire i. so the variance structure should be:

ai ~ 1/4 * A *sigma_square(a)
ei ~ 1/ni * sigma_square(e)

The residual variance is weighte by a diagonal matrix with element of 1/ni.
There are two variance components to be estimated. How should I conduct the analysis using ASREML?

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Received on Fri Dec 10 2009 - 05:51:39 EST